Roller Assembly

ABSTRACT

A roller assembly for a rolling door or similar device. The roller comprises a polymer and it has first and second sides, a rolling surface, and an axis around which the roller rolls. The roller also has an interior bore and a shaft rotatably coupled to the roller. One or more ferrules are received within one or both sides of the roller. The ferrules support and align the roller for rotation upon the shaft.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to roller assemblies, and, more particularly, to roller assemblies used in conjunction with flexible over head doors such as those found in garages and trucks.

2. Description of Related Art

A common type of flexible over head door has several elongated segments that are hinged together to form an enclosure for an opening or entrance to a building, commercial truck, or other enclosable area. The elongated segments typically have rollers secured to their lateral sides so as to allow the over head door to roll up and down within linear tracks located at each side of the enclosure. This configuration allows the door to roll from a vertical, lowered position to a horizontal, raised position, thereby allowing the door to open and close.

Many types of flexible over head doors are used in commercial environments and are therefore raised and lowered several times a day. In many types of flexible over head doors, ball bearings are used in the rollers for reducing friction between parts on the rollers. Nevertheless, frequent use results in significant wear and tear on the rollers of these doors. Parts thus need frequent replacing, and the doors need frequent maintenance. This, in turn, results in down time, expense, and reduction in efficiency for the users of these doors.

SUMMARY OF THE INVENTION

The present invention is directed toward a roller assembly having a roller, an interior bore, a shaft, and one or more ferrules. The roller has first and second sides, a rolling surface, and an axis around which the roller rolls. The roller also has an interior bore and a shaft rotatably coupled to the roller. One or more ferrules, each preferably shaped like a truncated trumpet, are coupled to one or both sides of the roller. In the preferred embodiments of the present invention, the roller assembly has two ferrules, one coupled to each side of the roller. Preferably, each side of the roller also has a recess for seating the ferrules, and the edges of the bore have a radial configuration that accommodates the outer surface of the ferrules. Also, in the preferred embodiments, the interior bore has grooves for catching or containing dust, dirt, or other particles that might enter the bore.

Preferred embodiments of the roller assembly also include a washer, preferably made of a polymer and situated on the shaft in between a ferrule and a shoulder disposed on the shaft. The roller is preferably made of a polymer, and the ferrule is preferably made of metal, and the shaft is preferably made of metal. Also, in the preferred embodiments, the shaft is cold-headed at its distal end so as to prevent the roller from falling off of the shaft. However, the roller may be secured to the shaft by any appropriate means.

Embodiments of the present invention also include a flexible door that has a plurality of roller assemblies coupled to it.

One significant advantage of the roller assembly of the present invention is that it does not need ball bearings. Also, the roller assembly has relatively few parts, does not require glue or special fixtures to assemble, and therefore it is cost-effective to produce, operate, and maintain. The roller assembly of the present invention exhibits long life, and during operation it is relatively quite as compared to the all metal roller assemblies of the prior art.

The foregoing and other features of the invention are hereinafter more fully described and particularly pointed out in the claims. The following description sets forth in detail certain illustrative embodiments of the invention, those being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.

BRIEF DESCRIPTION OF THE DRAWINGS

These and further features of the invention will be apparent with reference to the following description and drawings, wherein:

FIG. 1 is an exploded perspective view of a roller assembly in accordance with some embodiments of the present invention;

FIG. 2 is an elevational front view of a roller in accordance with some embodiments of the present invention;

FIG. 3 is a cross section, taken at line 3-3 in FIG. 2, of a roller in accordance with some embodiments of the present invention;

FIG. 4 is a side view of a ferrule in accordance with some embodiments of the present invention;

FIG. 4A is a schematic blown-up, broken-way view of a portion of the ferrule;

FIG. 4B is a cross-sectional view of the ferrule;

FIG. 5 is a side view of a shaft that has been cold-headed in accordance with some embodiments of the present invention;

FIG. 6 is a perspective view of the roller assembly of FIG. 1, except that the roller assembly shown in FIG. 6 has been assembled;

FIG. 7 is a second perspective view of the roller assembly of FIG. 6; and

FIG. 8 is an exemplary over head flexible door to which roller assemblies are attached in accordance with some embodiments of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows an exploded perspective view of one embodiment of a roller assembly 10 of the present invention. The roller assembly 10 basically comprises a roller 12, a shaft 14, and one or more ferrules 16. Preferably, as shown in FIG. 1, there are two ferrules 16. Also, in the preferred embodiments, a washer 18 is part of the roller assembly 10. All of these parts are assembled along an axis 20 so as to allow the roller 12 to rotate around the axis 20. The roller assembly 10 of the present invention is especially well suited for use in a flexible over head door such as a garage door or a rolling over head door on a commercial truck.

As can be seen, for example, in FIGS. 1-3, the roller 12 has first and second sides 22 a and 22 b, a rolling surface 24, and an interior bore 26 extending through the roller 12 and centered along the axis 20. The diameter of the interior bore 26 allows the shaft 14 to fit within the bore, as will be explained further herein. The rolling surface 24 comprises the surface of the roller 12 that contacts the track or surface upon which the roller 12 rolls. In one application the roller 12 rolls within a linear track 50, such as that shown in FIG. 8.

In the preferred embodiments of the roller 10, the interior bore 26 has radial edges 28. Preferably, both the edges of the bore 26 on side 22 a and the edges of the bore 26 on side 22 b of the roller 12 have a radial configuration, but some embodiments may have a radial edge 28 only on one of sides 22 a or 22 b. In the illustrated embodiment the shape of the radial edge 28 helps to seat the ferrules 16.

As illustrated, side 22 a of the roller 12 preferably has a recess 32. Also, side 22 b preferably has a recess 32. The recess 32 comprises a depression in the side 22 a and/or 22 b that is adapted to accommodate or receive the ferrule 16. In the preferred embodiments, the recess 32 comprises a circular depression that has a depth 22 c of at least 5% of the total maximum width of the roller 12.

The details of the configuration of ferrule 16 are best seen in FIGS. 4, 4B and 4C. As shown in FIG. 4B, ferrule 16 preferably includes an embossed portion 16 f that helps to strengthen the outer portion of the ferrule 16, and it also serves to minimize contact between the outer portion 16 f and the roller 12.

Also, in the preferred embodiments of the roller 12, the interior bore 26 has one or more grooves 30 for catching or containing dust, dirt, or other particles that might enter the interior bore 26. The grooves 30 thereby help to prevent the interior bore 26 from being scratched and damaged. Preferably as shown in the drawings, the grooves 30 resemble six semi-cylinders having axes that are parallel to the previously mentioned axis 20 of shaft 14. However, the grooves 30 can be of any appropriate shape and number suitable for catching dust or other particles.

The roller 12 is made of a polymer or rubber-like material. Materials that the roller 12 might be made of include, but are not limited to: thermoplastic materials such as polystyrene, acrylics, polyethylene, PET, urethanes, olefins including propylene homopolymer and copolymers, halogenated materials including PTFE and PVC, and engineering thermoplastics such as nylon, ABS, fluoropolymer, polyethetherketone, polyphenylene sulfide and polysulfone materials. A thermoset polymer may also be used such as an epoxy, a melamine, a polyester, a polyurethane or a urea containing thermoset. In a preferred embodiment roller 12 comprises a fairly rigid thermoplastic polyurethane compound.

The shaft 14 is preferably an elongated cylindrical bar made of some type of metal. One example of a preferred metal is low carbon steel (e.g., 1008 steel), but any suitable sturdy material may be used to comprise the shaft 14 such as, for example, aluminum, brass, copper or stainless steel. The shaft 14 fits through the interior bore 26 so as to allow the roller 12 to roll around the shaft 14. The shaft comprises an outer end 14 a, an inner end 14 b, and, preferably, a shoulder 14 c. The shoulder 14 c serves to prevent the roller 12 from slipping or moving towards the inner end 14 b of the shaft 14. The shoulder 14 c may comprise an integrally formed extension of the shaft 14 and not a separate part that has been coupled to the shaft 14. However, some embodiments of the present invention may comprise a separate shoulder 14 c that is coupled to the shaft 14 to prevent the roller 12 from moving towards the inner end 14 b. More particularly, the shoulder 14 c may comprise an adapter that serves to couple two separate pieces of shaft 14 a and 14 b together. By using an adaptor as part of the assembly, increased flexibility is afforded in that shafts 14 a and 14 b of various lengths can be selected to accommodate different applications and also rollers of various outer diameters can be used according to the requirements of a particular application. This concept is also shown in Espey U.S. Pat. No. 6,536,077 the disclosure of which in incorporated by reference herein in its entirety.

As mentioned previously, the preferred embodiments of the roller assembly 10 include a washer 18. The washer 18 is intended to help reduce or minimize friction between parts adjacent to it. Preferably, the washer 18 is generally ring-shaped and comprised of some type of polymer such as nylon, for example. However, the washer 18 may comprise a metal such as steel, copper, brass or bronze. Also, the roller assembly 10 is preferably assembled so that the washer 18 is located on the outer end 14 a of the shaft 14 between and adjacent to the shoulder 14 c and the ferrule 16 that is coupled to side 22 a of the roller 12.

The ferrule 16 serves to guide the shaft 14 there through and help to keep it aligned within the interior bore 26 of the roller 12. Preferably, the guiding surfaces of the ferrule 16 are curved so that the ferrule 16 is shaped like a truncated trumpet, as shown in the drawings.

As shown in FIG. 1, the roller assembly 10 preferably has two ferrules 16—one on each side of the roller 12. In the embodiment shown, each ferrule 16 is substantially identical and has a first inner edge 16a and a second outer edge 16 b. The ferrule 16 also includes an outer rolling surface 16c and an inner rolling surface 16 d. In the preferred embodiments, one or both of the ferrules 16 are disposed against the roller 12 so that inner edge 16 a seats within the interior bore 26 and outer edge 16 b seats at least in part within the recess 32 of one of the sides 22 a or 22 b of the roller 12. Also, the outer diameter of inner edge 16 a preferably substantially corresponds with the diameter of the interior bore 26, and the outer diameter of outer edge 16 b substantially corresponds with the diameter of the recess 32. The correspondence between the diameter of the interior bore 26 and the outer diameter of the edge 16 a helps to align the shaft 14 within the bore 26 and thereby reduce wear on the roller assembly 10. Also, such configuration allows two degrees of rolling, the roller 12 can roll on outer rolling surface 16 c, and the inner rolling surface 16d can roll along the outer surface of the outer end 14 a of the shaft 14.

As best seen in FIG. 4A the rolling surface 16 c has a tapered portion 16 m of decreasing diameter and a flat portion 16 n having a constant diameter. Tapered portion 16 m conforms in shape substantially to radial edge 28 of interior bore 16. Preferably, tapered portion 16 m extends along at least 25% and preferably along at least 35% of the width of the outer rolling surface 16 c. The height h of tapered portion 16 m is at least 5%, and preferably at least 8% of the diameter of the inner edge 16 a.

The ferrules 16 may be formed from any one of a variety of materials such as polymers or metals, however, in preferred embodiments of the present invention, the ferrule 16 is made of a metal that resists rust and wear such as stainless steel. A preferred stainless steel is grade 303. However, the ferrule 16 may be made of any other metal or suitably durable material such as a carbon steel, high strength brass or bronze. It will be appreciated that although ferrule 16 is preferably formed from a separate piece of metal or material, it would be possible to form one of the ferrules as an integral piece from shaft 14. For example, one could use forging techniques to integrally form the inner ferrule from shaft 14, and thus also eliminate the need for shoulder 14 c.

When the roller assembly 10 is assembled, as in FIGS. 6 and 7 for example, the roller 12 is able to rotate within the end 14 a of the shaft 14 and around the axis 10. The ferrules 16, whether there are one or more, preferably are seated snugly against the roller 12 and therefore rotate with the roller 12, but not too snuggly as to prevent the rotation of the ferrules 16. In the embodiments having a washer 18, the washer 18 preferably fits snugly around the shoulder 14 c of the shaft 14 and against the ferrule 16 coupled to side 22 a of the roller 12, as seen best in FIG. 7. The roller 12 is coupled to the shaft 14 so that the roller 12 does not slide off of the outer end 14 a of the shaft 14. In the preferred embodiments, the end 14 a of the shaft 14 is cold-headed to the roller 12, as will be explained hereafter. However, any suitable means for keeping the roller 12 on the shaft 14 may be employed, including but not limited to a spring retainer, or a press fit cap or threaded nut (not shown) coupled to the distal end of the shaft 14.

FIG. 5 shows a shaft 14 (minus the roller 12) that has been cold headed. In other words, the end 14 a of the shaft 14 has been forced or pounded outwardly so as to form a head 14 d and a lip 14 e. The lip 14 e is of a diameter greater than the diameter of the sections of the shaft 14 immediately adjacent to the lip 14 e. The lip 14 e therefore prevents the roller 12 from coming off of the outer end 14 a of the shaft 14. FIGS. 6 and 7 show two perspectives of an assembled roller assembly 10 in which the roller 12 is cold-headed to the shaft 14. In these embodiments, the roller 12 is shown to be snugly secured between the lip 14 e and the shoulder 14 c of the shaft 14.

In shall be noted that, in the preferred embodiments, the interior bore 26 is preferably lubricated with petroleum jelly or any other suitable lubricant that will not deteriorate the roller 12 yet still has sufficient viscosity to stick to the interior bore 26. Additional lubricant can be provided to the assembly 10 by using a lubricant infused polymer to produce roller 12.

FIG. 8 shows multiple roller assemblies 10 coupled to a flexible over head door or closure member comprising several elongated segments 52 that are coupled together to form an enclosure for an opening or entrance to a building, commercial truck, or other enclosable area. FIG. 8 shows the roller assemblies 10 coupled to the sides of the elongated segments 52 so as to allow the roller assemblies 10 to travel within tracks 50 and thereby allow the door to open and close. Preferably, the roller assemblies are coupled to a door that is designed, as in FIG. 8 for example, to move between a closed upright position to an open overhead position. However, some flexible doors of the present invention might move between a closed position to an open position that is to the side (instead of over head) of the closed position. Applicant hereby incorporates by reference U.S. Pat. Nos. 3,176,757 and 2,625,221 which disclose the general configuration of an over head door in which the roller assembly of the present invention may be employed.

While the preferred embodiment of present invention has been described herein with particularly, it is noted that the invention is capable of numerous modifications rearrangements, and substitutions of parts without departing from the scope and spirit of the present invention. Accordingly, the invention is not limited to the particular structures described herein, but rather is only to be defined by the claims appended hereto. 

1. A roller assembly comprising: a roller having a first side, a second side, and an axis around which said roller rolls; an interior bore formed in and through said roller and recesses formed along said first side and said second side; a shaft rotatably coupled to said roller and through said interior bore; and a first ferrule disposed within said recess of said first side of the roller; and a second ferrule disposed within said recess of said second side of the roller.
 2. The assembly of claim 1 wherein said ferrules are shaped like a truncated trumpet.
 3. The assembly of claim 1 wherein said bore further comprises radial edges extending from said interior bore of said roller to each of said recesses of such roller.
 4. The assembly of claim 1 further comprising means for preventing the roller from falling off of the shaft.
 5. The assembly of claim 1 wherein said shaft is cold-headed at one end in order to retain said ferrules and said roller on said shaft.
 6. The assembly of claim 1 further comprising a friction-reducing washer on said shaft for reducing friction between said shaft and said ferrule.
 7. The assembly of claim 6 wherein the washer is made of polymer.
 8. The assembly of claim 1 wherein said interior bore has dirt-catching grooves.
 9. The assembly of claim 8 wherein said dirt-catching grooves comprise a plurality of linear grooves within said interior bore.
 10. The assembly of claim 1 wherein said roller comprises polymer.
 11. The assembly of claim 1 wherein said ferrule comprises metal.
 12. A roller assembly comprising: a roller having a first side, a second side, and an axis around which said roller rolls; an interior central bore in said roller, said interior bore having a radial portion; a shaft; and a ferrule rotatably mounted upon said shaft and at least in part disposed within said interior central bore of said roller, said ferrule being shaped like a truncated trumpet.
 13. The assembly of claim 12 wherein said ferrule includes an outer rolling surface and an inner surface, and a tapered portion and a flat portion, the inner surface of the flat portion engages the shaft and at least a part of the outer surface of the ferrule rotatably engages the interior bore of the roller.
 14. The assembly of claim 13 wherein said tapered portion of said ferrule comprises at least 25% of the entire width of the outer rotating surface of the ferrule.
 15. The assembly of claim 12 wherein said roller includes a recess formed along the side of said roller, at least a portion of said ferrule being received within said recess.
 16. The assembly of claim 12 wherein said shaft comprises a first portion and a second portion, and an adapter joining said first and second portions.
 17. An overhead rolling door having the roller assembly of claim
 12. 18. A roller assembly comprising: a polymer roller having a first side and a second side, each side having a recess; a central axis around which said roller rolls; an interior bore disposed through said roller and centered along said central axis; a shaft for rotatably supporting the roller having a shoulder and an end for holding the roller upon the shaft; and a first ferrule seated in the recess of said first side and a second ferrule seated in the recess of said second side, the ferrules serving to align said shaft through said bore.
 19. The assembly of claim 18 including a washer on said shaft, said washer being located between said shoulder and the end of said shaft.
 20. The assembly of claim 18 wherein said end of said shaft comprises a cold-headed end that forms a stop for retaining the roller upon the shaft. 